Field of the Invention
The present invention relates to a portable seismic survey device and method for use in connection with reflection seismology for mapping subterranean formations.
Description of the Prior Art
It is known in the petroleum, gas, mineral and water exploration industries to use seismic geophysical surveys to map subterranean formations, such as but not limited to: stratigraphy of subterranean formations, lateral continuity of geologic layers, locations of buried paleochannels, positions of faults in sedimentary layers, basement topography, and others. These maps can be deduced through analysis of the nature of reflections and refractions of generated seismic waves from interfaces between layers within the subterranean formation.
Typically, a seismic energy source is used to generate seismic waves that travel through the earth and are then reflected by various subterranean formations to the earth's surface. At the surface, these reflected seismic waves are detected by an array of ground motion sensors, known as seismometers or geophones, which convert the detected waves into electrical signals. The electrical signals are stored and analyzed by a computer modeling system to determine and display the nature of the subterranean formations at a location surrounding the point the seismic waves were generated.
Known seismic energy source devices can be in communication with a global position system (GPS) or other telemetry systems to provide logging of the precise location and time of seismic wave generation. Typically, the seismic energy source device is controlled and activated automatically by the telemetry system, which can present a potential disadvantage since multiple error logs can occur by misfires of the seismic energy source device. Further disadvantage of these known systems is that the user does not having full control of the seismic energy source device since detonation is controlled by the telemetry system.
It has become desirable to extend drilling to locations that are environmentally sensitive or with limited vehicular access, which appear to overlay oil and gas formations. Thus portable seismic energy source devices have been developed and used.
It has been known to use vehicles that transport or tow a seismic source device from location to location. At a given location the seismic source is placed in direct contact with the ground. The seismic source device is activated to generate a seismic wave. However, the traditional seismic source devices are very heavy and thus need to be deployed by a vehicle, and they typically require large charges for creating a seismic wave that can travel deep through the Earth. As the environmentally sensitive areas prohibit or strictly limit the access of heavy duty equipment or vehicles, the existing methods for generating seismic waves are not suitable for these areas. These large systems are also undesirable for application in shallow wells that span large lateral distances.
Seismic data is critical to oil and gas companies during the exploration and development of oil and gas reserves. Seismic data is used from the earliest point in exploration right through the life of an oil or gas field, and in some cases even after the well has been abandoned. Seismic data is used for many different purposes; broad based analysis of prospective hydrocarbon basins, localized exploration of a prospective area, high resolution imaging prior to drilling a well, throughout the drilling process (including pore pressure prediction and micro-fracture analysis), and to enhance production as a field is developed and optimized throughout its productive life.
While the above-described devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not describe a portable seismic survey device and method that allows reflection seismology for mapping subterranean formations with detonation triggered event marking.
Therefore, a need exists for a new and novel portable seismic survey device and method that can be used for reflection seismology for mapping subterranean formations. In this regard, the present invention substantially fulfills this need. In this respect, the portable seismic survey device and method according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of reflection seismology for mapping subterranean formations.